The present invention relates to contour mapping systems for mapping the contour of an object. The invention is useful for mapping the curvature of the spine of a human being, for diagnosing spine deformities, such as scoliosis, and is therefore described below with respect to this application but could be used in many other applications. The invention also relates to a probe particularly useful in such a contour mapping system.
Scoliosis refers to a lateral spinal curve of a certain degree that affects an estimated 500,000 adults in the USA. The most common form of scoliosis, called idiopathic (i.e., of unknown origin) does not seem to have a real cause. There is a higher tendency to run in families with many more affected girls than boys; thus adolescent girls over the age of nine are five times more likely to be diagnosed with scoliosis than boys of the same age.
Early detection of the scoliosis can lead to effective treatment. Currently, scoliosis is treated by special braces, surgery, or by a combination of these techniques.
Screening for scoliosis detection has been adopted in most of the U.S. schools and in most of the Western World countries. Between 10 to 30% of the children that pass a simple examination at school are advised to visit a pediatrician/orthopedist for a more thorough investigation and eventually for a treatment recommendation. Approximately 30% of the latter are found to require long term treatment.
The basic tool for detecting scoliosis, and for quantifying the severity of the scoliosis, is the spinal roentgenogram (full length radiographs of the spine, one frontal and another sidewise). This is also the tool used by the physician during the long period of treatment and follow up.
Thus, a treated child will be exposed to a significant number of X-ray procedures, two to three double sessions per year. As a result, there is a concern about the late effects of this high dose radiation. Recent publications reveal a three to four times higher risk to develop breast cancer and a number of thyroid cancers in women undergoing repetitive X-ray exposures as part of their scoliosis treatment. In spite of efforts to reduce the radiation dose, there is still a higher lifetime risk of cancer from spinal radiographs among people with adolescent idiopathic scoliosis.
Therefore there is real need for an alternative device and system that will serve the same diagnostic purpose as the X-ray today but will eliminate the radiation exposure hazard especially for the young people. Multiple exposures during the long period of treatment are definitely a major factor that increases the risk of cancer.
A number of alternative systems have been developed, and are described in the literature, for measuring spine curvature in order to avoid the health hazard of radiation; see for example U.S. Pat. Nos. 2,324,672; 4,036,213; 4,600,012; 4,664,130; 4,760,851; 5,251,127; and 5,471,995. However, efforts are continually being made to develop systems and devices for measuring the spinal curve in a manner which enables more precision, and which can be performed more conveniently, than the existing systems.
An object of the present invention is to provide a novel contour mapping system for mapping the contour of an object in a convenient and simple manner. Another object of the invention is to provide a contour mapping system which is useful for measuring the curvature of the spine of human beings in order to detect and/or treat for spine deformities, such as scoliosis.
According to one aspect of the present invention, there is provided a contour mapping system for mapping the contour of an object, comprising: a probe constructed for application to a user""s hand with the outer tip of at least one finger of the hand movable along the outer surface of the object whose contour is to be mapped; a position sensor carried by the probe and movable therewith, and with the user""s hand, as the at least one finger of the hand is moved along the outer surface of the object; and a position tracking system for tracking the movement of the position sensor as the probe is moved with the user""s hand along the outer surface of the object.
One preferred embodiment of the invention is described below wherein the probe is constructed for grasping by the user""s hand with the tip of at least one finger in a fixed position with respect to the position sensor carried by the probe. The described probe includes a handle graspable by the user""s hand, and a finger supporting member fixed at one end of the handle for supporting the user""s index finger at the fixed position with respect to the position sensor carried by the probe. The position sensor is within the finger supporting member which member is fixed substantially perpendicularly to the handle at one end thereof for supporting the user""s finger with the tip of the finger exposed for direct contact with the outer surface of the object whose contour is to be mapped.
A second embodiment is described below wherein the probe is constructed for mounting on at least one finger of the user""s hand, with the position sensor at a fixed position with respect to the finger tip. In that described embodiment, the probe is constructed for mounting on two adjacent fingers of the user""s hand with the finger tips exposed for direct contact with the object whose contour is to be mapped.
In both embodiments described below, the object whose contour is to be mapped is the spine or the spinous processes of a person, and the system includes a data processor programmed to display data regarding the person""s spine as mapped by the probe. The data processor may also be programmed to compute and to display the distance between adjacent vertebras in the mapped spinal column, and/or the Cobb angle between adjacent vertebras in the mapped spinal column.
Further features and advantages of the invention will be apparent from the description below.